Rolling ladder brake



p 1934. D. E. WiLLARD 1,972,367

ROLLING LADDER BRAKE Filed June 9, 1932 2 Sheets-Sheet 1 P 1934- D. E. WILLARD ROLLING LADDER BRAKE Filed June 9, 1932 2 Sheets-Sheet 2 Patented Sept. 4, 1934 invenfi'onrel'atestotliat form of ladder commonly employed in stores, libraries, and other places having storage shelves for goods, books, and the like, at too great an elevation to be reached from the floor. In common with other ladders of the same type, my ladder is provided near the upper end with a wheel or wheels running upon a horizontal guide bar arranged in front of the shelves, and the lower ends of the ladder are provided with Wheels for supporting it from the floor and at the same time permitting it to be readily shifted parallel to the wall or to the shelves in connection with which the ladder is to be used. An objection to such ladders, frequently encounli5 tered in the past, is that they are apt to shift or slide suddenly when an effort is made to mount them, or when the user is reaching for the desired article and not infrequently a fall is the result. My invention has for its object to overcome this 219:? objection by providing means for releasably holding the ladder in adjusted position, and for this purpose the ladder of my invention is provided with a brake shoe, preferably spring pressed, which engages the above mentioned track bar and 5 holds the latter in position except when the brake is released for the purpose of shifting the ladder. In the drawings accompanying and forming a part of this specification, Fig. 1 is a side elevation of a ladder embodying my invention, the track bar being shown in vertical section,

Fig. 2 is a front elevation thereof, Fig. 3 is a top plan on an enlarged scale partly broken away,

Fig. 4 is a side elevation on an enlarged scale of 35 the upper portion of the ladder with the brake in looking position, the rail partly in vertical section on the line 4--4, Fig. 2,

Fig. 5 is a front elevation on the same scale of a similar portion of the apparatus partly in vertical section on the line 55, Fig. 1, and

Fig. 6 is a detail in plan, partially in horizontal section on the line 66, Fig. 5.

The ladder, proper, may be of any usual or approved construction and I have illustrated it 45: accordingly. In the form shown in the drawings the ladder 7 is provided with floor wheels 8 at the bottom of the respective side bars. The upper ends of the side bars of the ladder are provided as usual with track wheels 9 suitably mounted on the 50' ladder and engaging the horizontal track bar 10,

for guiding and supporting the upper end of the ladder.

Upon the upper end of one of the side bars of the ladder is secured a bracket, the outer edge of 5 which is formed into a dovetailed, guide bar 13.

The casting; 14.:which supports 5 the =brake adevice, to be presently described, is formed with corresponding dovetailed flanges 15, 16 which embrace guide 13 and permit the free movement of the casting in a direction substantially parallel to the side bars of the ladder. In the preferred embodiment of the invention a roller 1'? is journaled upon the casting in a position to engage the track bar pin on its upper side and to form an abutment between which and the brake shoe the track may be clamped, the roller being journaled upon a pin 18 mounted in the casting. The casting is also formed with transverse webs or bars 19, 20 which are perforated, the perforations being in registry to receive and guide the spindle 21 on which the brake shoe 22 is mounted. Preferably, the brake shoe is provided with a friction facing 23.

The lower end of the casting is formed with spaced guide lugs 24, 25. In the construction shown, shoulders 26, 27 are constituted by the under surface of the transverse Web 20. A coil compression spring 28 surrounds the brake spindle 21, between the webs 19, 20. At its upper end the spring, bears upon the collar or washer 30 attached to the spindle, and at its lower end the spring bears against a washer 32 loosely surrounding the spindle and resting upon the cross web 20. The spring normally forces the brake shoe into contact with the track rod.

For the purpose of releasing the brake when desired, to permit the shifting of the ladder along the track, a lever 32 is pivoted to the lower end of the spindle 21 and bears against the casting at one end. In the specific example given, the lever is bifurcated at 34, the two branches or forks embracing the spindle and also the guide lugs 24, 25 of the casting. The lever is pivoted to the spindle at 33 by a pin extending through both forks of the lever and the spindle and the ends of the forks are upturned and rounded at 35 and the movement thereof in one direction is limited by the shoulders 26, 27 of the casting. Preferably the outer end of the lever is formed with an eye 37 from which depends a pull chain 38.

By reason of its sliding connection to the bracket on the ladder the brake is free to adjust itself and prevent binding on the track bar. When it is desired to shift the ladder a pull on the chain is sufficient to release the brake and when the chain is again released the brake engages the track bar, the roller 17 furnishing an abutment between which and the brake shoe the track bar is firmly gripped.

I claim:

1. In aladder of the class described, the combination with a horizontal track bar, means normally supporting the ladder on said track bar, a bracket on the ladder, a casting mounted to slide upon the bracket, a roller mounted upon the casting and adapted to engage the upper surface of said track bar, a brake shoe adapted to engage the under surface of said track bar, a spindle on which the brake shoe is mounted, a spring intermediate the spindle and the casting, and a lever pivoted on the spindle and engaging the casting for retracting the brake.

2. In a ladder of the class described, the combination with a horizontal track bar, means normally supporting the ladder on said track bar, a casting mounted to slide vertically upon the upper end of the ladder, a roller mounted upon the casting and adapted to engage said track bar on one side thereof, a brake shoe adapted to engage the opposite side of said track bar cooperatively with said roller, a reciprocable spindle on which the brake shoe is mounted, a spring engaging the brake shoe and normally forcing it into contact with said track bar, and a lever engaging the spindle and adapted to operate it to withdraw the brake sho'e from contact with the track bar.

3. In structure of the class described, the combination with a track bar, of a ladder member, means for mounting one end of said ladder member for free slide movement along said track bar, a brake supporting member, means for mounting said brake supporting member upon said ladder for slide movement lengthwise of the ladder, a roller mounted on said brake supporting member adapted to engage one side of said track bar, a brake shoe carried by said brake supporting member and engaging the opposite side of said track bar cooperatively with said roller, means constantly urging said brake shoe against said track bar, and means for actuating said urging means to'release said brake shoe.

DONALD E. WILLARD. 

